This invention generally relates to drive sockets and drive socket forming processes and particularly concerns female drives having retention recesses for hand, power and impact wrenches and the like and an improved method of forming such drives.
Various processes have been used in the past in forming socket wrenches, extension bars, adapters and the like. These devices such as the socket wrench itself are standard devices, well known in the art. A conventional square drive socket is provided at one end of the socket wrench and is releasably attachable to a drive tang of a handle unit for a ratchet, for example. A fastener socket is coaxially formed at an opposite end of the wrench. The fastener socket is commonly serrated or of hexagonal crosssection. A through-hole may extend between the coaxially aligned sockets. The through-hole serves to provide clearance, for example, for a shank of a bolt on which a hex nut is threadably engaged with the nut received within the hex fastener socket. For a quality product, such socket wrenches are formed of alloy steel. Standard screw machines conventionally have been used in the manufacture of such wrenches which normally require several sequential machining operations.
Drive socket openings for such wrenches commonly have a recess for receiving a spring-operated ball, for example, in a tang of a drive handle for retaining the socket wrench and handle attachment in driving engagement. However, problems are frequently encountered in forming such recesses in socket wrenches and the like because of long standing difficulties in achieving consistency and accuracy in the size, shape and location of a recess in a face of the drive socket opening while also insuring that the depth of the recess is consistently accurate, particularly when each face of the drive opening has a recess. Specifications for female ends of such square drives for hand, power and impact wrenches are set forth in Table 7, The American Society of Mechanical Engineers publication ASME B107.4M-1995.
When such parts are being produced by machining operations such as turning or index milling operations, for example, how one sets a cutter and how one sets the travel of the cutter are variable but important functions. If the drive opening is not precisely dead center relative to a major longitudinal axis of the workpiece or if the cutting tool itself is somewhat off center, any resulting product will be nonconforming because the recesses are of different depth, or the recesses are misaligned from a symmetrical centered position in the faces of their respective drive opening, or the recesses are not axially aligned relative to the major longitudinal axis of the part. Moreover, such machining processes require specialized equipment, are expensive if not fully automated, suffer from limited tool life and resultant defects such as burrs.
One object of this invention is to provide an improved drive socket having a unique recess of predetermined depth in a face of a drive socket opening with the recess precisely located in desired symmetrical relation to a face of the drive socket opening. Included in this object is the aim of providing an improved method of making such a drive socket.
Another object is to provide an improved drive socket having a plurality of drive faces within a drive opening wherein every face has a recess formed at an identical depth and location relative to the recesses in the other faces and a method of making such a drive socket.
Still another object is to provide an improved method of making a recess in a face of a drive opening of a drive socket of high quality in a simplified manufacturing process of reduced cost and which eliminates commonly required secondary machining operations.
Other objects will be in part obvious and in part pointed out more in detail hereinafter.
This invention is directed to a method of making a drive socket with a recess in its drive opening for use in retaining the drive socket on a complementary handle attachment and includes a series of steps. A metal workpiece is first provided having a drive opening with a face extending inwardly from one end of the drive opening. A metal forming step forms a groove along at least a portion of the length of the face of the drive opening, followed by moving material from the groove surface along only a portion of the length of the groove and gathering the moved material to form a ledge between ends of the groove such that a recess is defined by the groove extending beyond the ledge.
This invention also is directed to a drive device having a metal socket with a drive opening having a face extending inwardly from adjacent one end of the drive opening. A groove extends along at least a portion of the face of the opening. A ledge protrudes radially inwardly from the groove between ends of the groove such that a recess is defined by that portion of the groove extending beyond the ledge.